Five protesters burst into the House of Commons during a debate on banning fox hunting Wednesday, while thousands of hunting enthusiasts massed in a noisy demonstration outside — some of them clashing with police in riot gear.

The protesters, wearing white T-shirts, managed to reach the floor of the Commons chamber and run toward the central box where government ministers and opposition leaders speak. Guards grabbed them and hustled them out, and the debate resumed after about 30 minutes.

The invasion of the House of Commons (search) came two days after another embarrassing security breach when a protester dressed as Batman (search) climbed up a ledge at the front of Buckingham Palace.

"Nobody has ever got near the floor of the House before," said John McWilliam, a member of parliament for the Labour Party.

"We were supposed to have a tightening up of security after the purple powder escapade — clearly it has not happened, especially on a day when the threat was materially higher than on that occasion," McWilliam said.

A few months ago, another protester, like "Batman" demonstrating for fathers' child-custody rights, emptied a bag of purple powder from a visitors' balcony onto the Commons floor below.

Outside, on the grassy Parliament Square (search), some 10,000 people blew horns and waved banners in support of the controversial rural sport. Scuffles broke out as some protesters surged against a police line blocking the crowd from crossing the road to Parliament's ornate gates.

Police drew batons and exchanged blows with some protesters, who had thrown wooden placards. Blood poured down the heads of some demonstrators, and red smoke wafted between rows of police vans after demonstrators apparently hurled a smoke bomb.

It was a dramatic demonstration of the passions aroused in the debate about hunting foxes and other prey with dog packs.

Opponents say it is a barbaric practice that has no place in modern society. Supporters say the government, which has vowed to outlaw the sport, is needlessly meddling in their rural way of life.

"I don't know how it started, but the crowd kept pushing, so the police started hitting people," said Andrew Vernon, 25, who had come to London from Scotland. "I saw girls getting hit just like me. There were probably about 20 of us getting hit up there. It was just disgusting."

Scotland Yard (search) police headquarters could not immediately say how many people were arrested.

The government has allowed just one day to rush the Hunting Bill (search) through the House of Commons and says it won't let the House of Lords, Parliament's unelected upper chamber, block the legislation as it has done in the past.

British Prime Minister Tony Blair's government came to power in 1997 promising lawmakers a free vote on whether to outlaw the sport.

An overwhelming majority of lawmakers in the House of Commons support the ban on the centuries-old sport, in which scarlet jacketed horsemen pursue foxes across the countryside with packs of baying hounds, and it is likely to be enforced by July 2006.

"I think it is a scandal," said Peter Oliver, who has ridden with the hounds in rural Dorset, southern England, for 20 years. "It is totally undemocratic. I think foxes have to be killed, and if hunting stops, the population will increase and they will either starve to death or be shot by farmers."

Fox hunting polarizes Britain between town and country, and agitates the class antagonisms that simmer below the surface of British society.

While the royal family and many others delight in hunting, opinion polls show most Britons believe it's cruel.

Several hours have been set aside Wednesday for lawmakers to debate the bill. They will also vote on a government proposal to delay the date the ban takes effect, to allow employees of some 200 hunts around the country to find alternative employment and thousands of fox hounds to be rehoused.

Mike Wilkinson, sitting outside the Commons wearing a wax jacket, said a ban would destroy the fabric of rural life.

"The issue is much broader than just hunting with dogs," he said. "It will affect farriers, saddlers, hay makers and blacksmiths. It is inevitable that this will become an election issue."

Rural campaigners insist they will challenge a ban in court if the government uses the Parliament Act to prevent peers from blocking the bill.

Once a ban is enforced, Tim Bonner of the pro-hunting Countryside Alliance (search) said campaigners would deliberately flout the new law and, if arrested, would challenge it under European human rights legislation.

Monday's protest at Buckingham Palace was staged by Fathers 4 Justice (search), a group advocating stronger rights for divorced and separated fathers, which also disrupted the Commons on May 19 when two members threw purple flour at Prime Minister Tony Blair.

One of those men, Ron Davis, was convicted of disorderly behavior on Wednesday, placed on two years probation and ordered to pay $800 in costs.